Smoke detection is presently concerned primarily with aerosol content of smoke produced by burning of material under different conditions which significantly affect aerosol property of the smoke, such as particle size and distribution quantified in terms of percentage obscuration involving the interaction of light wave radiation with the smoke aerosols producing scattering and absorption of the light waves due to the presence of the smoke. Currently there are two basic types of smoke detectors used for fire detection purpose when smoke density exceeds a certain threshold. One of such smoke detectors is of an ionization chamber type within which radioactive, charged plate electric field is established through which ionized air molecules migrate to trigger a fire indicating alarm. Such smoke detectors however have a high false alarm rate tendency caused by airborne dust and water droplets. False alarms caused by airborne dirt or water droplets are applicable to the other types of photoelectric smoke detectors, wherein smoke particles entering an optically powered illuminated test chamber scatter light in all directions causing light collection. It is therefore an important object of the present invention to provide a smoke detector which avoids the aforementioned false alarms and other disadvantages associated with the ionization chamber and aforementioned photoelectric types of smoke detectors.